This application requests continued support for the NIEHS Center at the University of Texas Medical Branch. The mission of this Center is to integrate, coordinate and foster interactions and collaborations among a group of established investigators pursuing research pertinent to the effects of environmental factors on humani health. Our proximity to sources of many significant environmental problems, such as ozone pollution, i emissions of fine particulates, hazardous chemical releases, hazardous waste sites, and pediatric lead exposure, makes UTMB a compelling site for a multidisciplinary environmental health sciences center. During the nine years of its existence, this Center has emerged as a national leader in elucidating cellular response mechanisms to environmental challenge and in working with the community to enhance awareness of environmental health issues and to elaborate prevention and intervention strategies. The overarching theme of the UTMB NIEHS Center is the role of oxidative stress in mediating the health effects of exposure to environmental factors. Investigators in the four Research Cores are studying the mechanisms by which reactive oxygen species are produced and detoxified (Biotransformation Research Core), modulate signaling pathways (Oxidative Stress and Signaling Research Core), damage DNA (DNA Repair and Mutagenesis Research Core), and are involved in the etiology of Asthma (Asthma Pathogenesis Research Core). In pursuing these research directions, Center Investigators are aided by four Service Cores (Molecular Genetics, Biomolecular Resource Facility, Cell Biology, and Synthetic Organic Chemistry), which provide advanced technologies, unique reagents, and specialized expertise, as well cost-effective and efficient access to more routine services or research materials. Scientific findings from the Center are communicated to the public through a vibrant Community Outreach and Education Program (COEP) with advice from a Community Outreach Board. The various activities of the NIEHS Center are coordinated by an Administrative Core, which receives input from an Internal Advisory Board, External Advisory Board, and Director's Advisory Council, and oversees a variety of development programs including Pilot Projects, seminars, and workshops.